During the mass production of articles made from sheet-type work material, such as fabric, one or more layers of fabric are typically spread onto what is referred to by those skilled in the art of fabric processing as a spreading table. The fabric is then moved, often via a conveyor, onto a support surface forming part of a work material processing apparatus like a cloth cutting machine. A cloth cutting machine can be used to cut the fabric into pattern pieces for use in garments, furniture or other articles.
Generally, the pattern pieces are positioned on the spread fabric in a spatial array of segments positioned in a cutting sequence. This spatial array of segments is referred to by those skilled in the art as a “marker.” Usually markers are computer generated to optimize piece pattern density and thereby minimize the waste of fabric.
However, in a garment or upholstery cutting application, it is sometimes necessary to align a point on a garment or furniture segment with a particular point on the fabric. This is known in the industry as a “fabric match” or a “match to fabric”. Often, a match to fabric is carried out so that a garment or furniture pattern piece is centered relative to a particular pattern defined by the fabric. Sometimes, a further requirement, is that the extremities or end portions of the pattern piece are also positioned symmetrical with respect to the pattern defined by the fabric. If the fabric involved has a uniform repeat pattern, then positioning a center point of a symmetrically shaped pattern piece at a center point of the pattern defined by the fabric will suffice to ensure that the end portions of the pattern piece are also symmetrical with respect to the pattern defined by fabric.
However, fabrics having a plaid or stripe repeat pattern normally are non-uniform in either a warp or weft direction with respect to the pattern defined by the fabric. Accordingly, if a pattern piece having symmetrical dimensions is positioned on a fabric by locating a center point of the pattern piece with respect to a plaid or stripe repeat pattern that is not uniform, and cut from the fabric, the resulting pattern piece may appear to be asymmetrical with respect to the pattern defined by the fabric when comparing certain portions of the pattern piece. For example, opposing end portions of a symmetrically shaped elongated pattern piece having a central point of the pattern piece centered with respect to a repeat pattern defined by a fabric may appear at the end portions thereof to be asymmetrical with respect to the repeat pattern due to variations in the repeat pattern defined by the fabric.
Prior art marker generating and cutting systems do not provide for establishing or adjusting a marker for ensuring symmetry with respect to associated portions of a pattern piece relative to a repeat pattern defined by the work material.
Based on the foregoing, it is the general object of the present invention to provide a method for positioning a pattern piece relative to sheet-type work material defining a repeat pattern that overcomes the problems and drawbacks of prior art methods.